Ftdiun2k.ini

Here’s a full write-up covering ftdiun2k.ini — its purpose, structure, typical usage, and relevance in penetration testing / red teaming.

1. Overview ftdiun2k.ini is a configuration file associated with FTDI Un2K , a tool used to interface with FTDI (Future Technology Devices International) USB-to-serial converter chips. It is most notably referenced in the context of ChipWhisperer (an open-source side-channel analysis tool) and certain hardware hacking setups. In offensive security, the file sometimes appears in attack chains involving USB-based keystroke injection or USB emulation attacks (e.g., BadUSB, Rubber Ducky), where FTDI chips are reprogrammed to act as Human Interface Devices (HIDs).

2. File Purpose ftdiun2k.ini stores configuration parameters for the ftdiun2k utility, which:

Reprograms FTDI EEPROM settings. Changes USB descriptors (vendor ID / product ID / string descriptors). Alters device behavior (e.g., from serial port to HID keyboard/mouse). ftdiun2k.ini

This is used legitimately for development but can be weaponized to make a USB device appear as a keyboard to bypass host protections.

3. Typical File Structure A standard ftdiun2k.ini might contain: [EEPROM] VID=0x0403 PID=0x6001 MANUFACTURER="FTDI" PRODUCT="USB<->Serial Converter" SERIAL_NUMBER="FT123456" [HID] ENABLE_HID=1 KEYBOARD=1 MOUSE=0 [FLASH] EEPROM_SIZE=128

Key parameters: | Section | Parameter | Meaning | |---------|-----------|---------| | [EEPROM] | VID , PID | Vendor/Product ID (changes device type) | | [EEPROM] | MANUFACTURER , PRODUCT | USB strings visible to OS | | [HID] | ENABLE_HID | If 1, device presents as HID instead of serial | | [HID] | KEYBOARD / MOUSE | Which HID types to emulate | | [FLASH] | EEPROM_SIZE | Chip-specific size in bytes | Here’s a full write-up covering ftdiun2k

4. Attack Use Case BadUSB via FTDI chip:

Attacker obtains a USB device with an FTDI chip (e.g., FT232). Edits ftdiun2k.ini to set ENABLE_HID=1 , KEYBOARD=1 . Runs ftdiun2k with the malicious .ini to reflash EEPROM. Device now enumerates as a keyboard. Payload script (e.g., PowerShell download cradle) is sent via HID keystrokes.

This bypasses many software USB firewalls that only block mass storage or network devices but allow keyboards. It is most notably referenced in the context

5. Detection & Mitigation Defensive measures:

USB device whitelisting (e.g., only allow known VID/PID). Disable auto-run of HID macros (some OS settings). Endpoint protection monitoring for rapid keystroke injection (anti-BadUSB). Physical USB port control (block unknown devices).